The Easy Knowledge Blog

On the results disclosed so far, weight loss trails the front-runners, but the latecomer is betting on price and gentler stomach side effects

🎧 Post Summary

Korea’s obesity drug market reached 819.5 billion won last year, more than tripling in a year, and Wegovy and Mounjaro hold about 86% of it. Now Hanmi Pharmaceutical’s ‘Ephe’, Korea’s first homegrown GLP-1 obesity drug, is stepping in. If it wins approval from the Ministry of Food and Drug Safety (MFDS) in October, launch preparations will start right away. So what does Ephe have in common with the existing drugs, and how does it differ? We line up efficacy, side effects and price side by side, and review what experts expect. This post is for information only. The choice and use of any drug should be decided in consultation with a doctor.

① What kind of drug is Ephe?

GLP-1 is a hormone released from the gut after a meal. It acts on the appetite center of the brain to increase fullness and reduce how much you eat. Wegovy, Mounjaro and Ephe are all once-weekly injections built on this principle. Ephe (generic name efpeglenatide) was developed in-house by Hanmi Pharmaceutical and uses the company’s long-acting platform technology, ‘LAPSCOVERY’, which keeps the drug active longer. Like Wegovy, it is a single-action drug that targets only the GLP-1 receptor, whereas Mounjaro is a dual agonist that acts on both the GIP and GLP-1 receptors.

Hanmi filed for marketing approval in December last year, and the drug has been designated for the MFDS’s fast-track review program for global innovative products (GIFT). The company applied for five strengths, 2, 4, 6, 8 and 10 mg, in 0.5 mL single-use auto-injectors, for adults with obesity who do not have diabetes. Starting doses and dose-escalation intervals will be set in the product label after approval. The plan is to launch within about a month of an October approval, and the official target is a launch within this year. Production will be handled at Hanmi’s Pyeongtaek Bio Plant.

② Efficacy — how much weight comes off?

Ephe’s Phase 3 trial is a randomized, double-blind, placebo-controlled study of 448 Korean adults with obesity and no diabetes. The full study is designed to run 64 weeks, and what has been disclosed so far is the interim result at week 40. Among the 446 patients in the efficacy analysis, body weight in the Ephe group fell by an average of 9.75%, versus 0.95% in the placebo group. Some 79.42% of patients lost at least 5% of their body weight, 49.46% lost at least 10%, and 19.86% lost at least 15%. Among women with a body mass index (BMI) below 30, the average reduction was 12.20%, the highest among the subgroups analyzed.

For comparison, in the STEP 1 trial of 1,961 adults, Wegovy produced an average reduction of 14.9% after 68 weeks, with 86.4% of patients losing at least 5%, 69.1% at least 10% and 50.5% at least 15%. In the SURMOUNT-1 trial of 2,539 people, Mounjaro’s average reduction after 72 weeks was 15.0% at 5 mg, 19.5% at 10 mg and 20.9% at 15 mg; in the 15 mg group, 70.6% lost at least 15% and 56.7% lost at least 20%.

Still, it is hard to line these numbers up and declare a winner. The trials differ in length, population and design, and Ephe’s data are still interim. Kiwoom Securities judged that, once the placebo effect is removed, Ephe’s -8.13% (40 weeks) and Wegovy’s -8.5% (a 44-week trial in Asian participants) look similar in an indirect comparison. Professor Kim Kyung-gon of Gachon University Gil Medical Center, on the other hand, said that in terms of ‘weight-loss target’, Ephe is comparable not to Wegovy or Mounjaro but to the existing oral combination obesity drug Qsymia, which produced an average loss of 9.8 to 10.9% over 56 weeks.

③ Side effects — what to watch for

For all three drugs, the most common side effects are digestive symptoms such as nausea, vomiting, diarrhea and constipation. The drugs slow the emptying of the stomach and affect appetite and fullness signals, so these symptoms are common early in treatment or when the dose is raised, and mostly ease over time. In Ephe’s Korean Phase 3 trial (40 weeks), nausea was reported in 16.72% (placebo 5.37%), vomiting in 11.71% (placebo 2.01%) and diarrhea in 17.73% (placebo 4.7%). Hanmi says the overall rate of digestive side effects was 50%, lower than in the Wegovy trial.

In the Wegovy STEP 1 trial, nausea was 44.10% (placebo 17.40%), vomiting 24.58% (placebo 6.56%), diarrhea 31.47% (placebo 15.88%) and constipation 23.35% (placebo 9.47%). For Mounjaro, US FDA approval documents report nausea of 25 to 29% (placebo 8%) and vomiting of 8 to 13% (placebo 2%). In the 72-week SURMOUNT-5 trial, which compared Wegovy and Mounjaro head to head, treatment discontinuation was 6.1% for Mounjaro and 8.0% for Wegovy, and discontinuation due to digestive symptoms was 2.7% and 5.6%, respectively. However, the Ephe and Wegovy figures come from different trials, so no verdict on relative safety can be drawn, and data on Ephe’s constipation and other adverse events, as well as its long-term safety, have not yet been fully disclosed.

There are also cautions that apply across the GLP-1 class. Gallstones and cholecystitis were reported at 1.6% (placebo 0.7%) and 0.6% (placebo 0.2%) in Wegovy trials, and at 1.1% (placebo 1.0%) and 0.7% (placebo 0.2%) for Mounjaro. On acute pancreatitis, a large study of about 66,000 people found a slightly higher risk among users of GLP-1 obesity injections, but there is still no clear evidence that the drugs directly damage the pancreas, and some analysts say it may be a side result of rapid weight loss. Mounjaro’s labeling in Korea also warns that severe dehydration from vomiting and diarrhea can lead to acute kidney injury. Item-by-item figures like these have not yet been disclosed in detail for Ephe, so the product label should be checked after approval. The MFDS is moving to designate these GLP-1 obesity drugs as ‘drugs of concern for misuse and abuse’.

④ Price and supply — why price is the battleground

Obesity drugs are not covered by national health insurance, so patients pay the full cost. At pharmacies in Seoul, a month of treatment costs roughly 200,000 to 400,000 won for Wegovy and 300,000 to 700,000 won for Mounjaro. The ex-factory price for four weeks at the starting dose is 216,000 won for Wegovy (0.25 mg) and 278,000 won for Mounjaro (2.5 mg). Hanmi has not disclosed Ephe’s supply price, but the industry is talking about a level of around 100,000 won for four weeks. The rationale is that in-house production can cut manufacturing and distribution costs.

The wild card is how the incumbents respond. Ahead of Mounjaro’s Korean launch, Wegovy cut its starting-dose supply price by about 42%, from 372,000 won to 216,000 won. A price war could break out again once Ephe arrives. On supply, domestic production is seen as a strength. Wegovy and Mounjaro have both run short of some doses since launching in Korea because of strong demand, while Hanmi plans to respond flexibly to changes in demand with its own production system.

⑤ The three drugs at a glance

Here is the comparison in one table. Clinical results come from different trials, so treat them as reference only.

Category	Ephe	Wegovy	Mounjaro
Ingredient (maker)	Efpeglenatide (Hanmi Pharmaceutical)	Semaglutide (Novo Nordisk)	Tirzepatide (Eli Lilly)
Mechanism	GLP-1 only	GLP-1 only	Dual GIP and GLP-1
Dosing	Once weekly (filed as an auto-injector)	Once weekly	Once weekly
Weight loss in key trial	Korean Phase 3, 40 weeks (interim): 9.75%	STEP 1, 68 weeks: 14.9%	SURMOUNT-1, 72 weeks: 15.0 to 20.9%
Nausea / vomiting / diarrhea	16.72% / 11.71% / 17.73%	44.10% / 24.58% / 31.47% (STEP 1)	Nausea 25 to 29%, vomiting 8 to 13% (FDA documents)
Starting dose, 4-week price	Undecided (around 100,000 won mentioned)	216,000 won	278,000 won
Manufacturing	Domestic (Pyeongtaek)	Imported	Imported
Strengths	Expected price edge, domestic production, Korean-only Phase 3, lower digestive side effects observed	Longest prescribing track record, research supporting fewer cardiovascular events	Largest weight loss, lower discontinuation in a head-to-head comparison with Wegovy
Weaknesses	Smaller weight loss on interim data, limited long-term data and prescribing experience	Smaller weight loss than Mounjaro, shrinking share of prescriptions	Highest price range, nausea and vomiting can be stronger early on

⑥ What do experts expect?

First, the view from clinical practice. Professor Kim said it is a positive that a new drug widens prescribing options at a time when high drug prices make it hard for patients who really need treatment to start it. But he expects the launch to have little immediate effect on prices of imported obesity drugs, and said gradual price stabilization can be hoped for over the longer term as more treatments arrive and competition intensifies. A pharmaceutical industry source also said Ephe has differentiators in price and in clinical data from Korean patients, but that Wegovy and Mounjaro have high awareness and prescribing experience, so the key is how far Ephe can change the choices of doctors and patients in actual practice.

The brokerage community is relatively upbeat. Hanmi has given 2027 sales guidance of around 100 billion won for Ephe, and KB Securities analyst Shin Ji-hoon said that given the steep growth of Korea’s obesity drug market, exceeding that guidance is possible. Some in the industry also see price competitiveness as the decisive weapon, and say that the company’s ability to raise utilization of the Pyeongtaek plant and prove mass-production cost savings will be a key yardstick for re-rating its corporate value.

The biggest outside variable is the oral obesity pill. Novo Nordisk’s Wegovy pill (semaglutide) and Eli Lilly’s Foundayo (orforglipron) have already filed for approval with the MFDS, and the industry expects a Korean launch next year. Oral versions are usually cheaper than injections, which could heat up price competition further. It is also worth remembering that market rankings can flip at any time. Mounjaro, a latecomer, overtook Wegovy in Korea, and as of June this year its share of prescriptions had widened to about nine to one.

Hanmi has also laid out a roadmap beyond Ephe. Follow-on candidates include HM17321, a muscle-gain obesity treatment, and HM15275, a triple agonist that acts on the GLP-1, GIP and glucagon receptors at the same time. HM15275 is in a Phase 2 trial in the United States, expected to finish in the first half of 2027, with a commercialization target of 2030. Analysts say that securing market share and contact with physicians through Ephe would let Hanmi lean on its existing sales and marketing base when it brings the next generation to market.

Good to Know

• Ephe is not yet approved. The timing of approval, launch date and price are not confirmed, and a price around 100,000 won is only an industry expectation.
• Comparing weight-loss rates and side-effect rates from different clinical trials as if they were the same test can be misleading. Ephe’s published figures are interim results at week 40.
• Obesity drugs are prescription medicines that require a doctor’s diagnosis and prescription. Whether to take one, and at what dose, should be decided with a medical professional based on your own health.
• If you have severe abdominal pain, repeated vomiting that keeps you from even drinking water, or high fever and jaundice, do not dismiss it as an ordinary side effect. Seek medical care right away.
• Drug prices and the market landscape could change quickly, for example with the launch of oral obesity drugs, so it is wise to check for the latest information.

In sum, Ephe is not a drug trying to beat the front-runners on the size of weight loss. It is a drug trying to pry open a gap in the market with price, stable supply, data from Korean patients and comparatively lower digestive side effects. Its success will depend on the final 64-week results, its reception in real-world prescribing, and the final supply price. Add the incumbents’ price responses and the arrival of oral obesity drugs, and Korea’s obesity drug market from next year onward is likely to become a far more complicated contest than today. As choices widen, it matters for patients to weigh efficacy, side effects and cost together with their doctors.

References

• Newspim — “위고비·마운자로 86% 장악…한미약품 ‘에페’ 가격으로 틈새 공략” (newspim.com, in Korean)
• Hidoc — “국산 1호 GLP-1 비만약 나온다…한미 ‘에페’ 연내 출시 목표” (news.hidoc.co.kr, in Korean)
• Money Today — “비만약 더 싸진다…경구용·한미 ‘에페’ 출시 대기” (mt.co.kr, in Korean)
• Asia Today — “비만약 ‘에페’ 출시 앞둔 한미약품… 수율·원가절감 관건” (asiatoday.co.kr, in Korean)
• Womansense — “위고비·마운자로 열풍…놓치면 안 되는 부작용 6가지” (womansense.co.kr, in Korean)
• Bizwatch — “먹는 비만약 국내 상륙 초읽기…파운다요·위고비필 ‘격돌’” (news.bizwatch.co.kr, in Korean)
• ClinicalTrials.gov — “STEP 1: Research Study Investigating How Well Semaglutide Works in People Suffering From Overweight or Obesity” (clinicaltrials.gov)